phpBB : Erro Crítico

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO f_activesessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('97ea1818dd04bf3c8e4f441c40e870c6', -1, 1768768468, 1768768468, 'd849d854', 1, 0, 0)

Line : 187
File : sessions.php